Patent GB-925628-A (GB)
Title: Improvements in or relating to means for automatically regulating the driving power and/or driving torque of variably driven machines and like loads
IPC: B41F13/00
Filed: 1959-07-27
Abstract: 925,628. Hydraulic transmissions. W. REIMERS. July 27, 1959 [Aug. 16, 1958], No. 25634/59. Class 69 (2). [Also in Group XXIV] In agitators, conveyers, strip or web-processing, winding or unwinding machines, driven at varying speeds by at least one constant speed-driving member, follow-up means automatically regulating driving power and/or torque in accordance with a predetermined fixed or varied value and arranged between said driving member and the driven machine comprises an infinitely variable speed gear which may be hydraulic or mechanical such as an expanding conical pulley gear 10 shown, a torque measuring device controlling means, such as a potentiometer 40, to convert measuredtorque value into a corresponding voltage, a torque demand control potentiometer 50, and a relay R responsive to difference in the opposed voltages from the potentiometers 40, 50 to actuate a motor 16 regulating the variable speed gear 10, through bearing 15, to vary the torque at the torque-measuring device in a sense to annul the said voltage difference. The torque-measuring device may comprise means measuring torsion bar twist or the turning movement of a suitably mounted housing of the variable speed gear or a fixed-ratio intermediate gear, or a spur, or, as shown, bevel planet gear device 20 having a reaction arm 31 retained by an adjustable spring 35, damped by a dash-pot 32 and forming the tapping of the potentiometer 40. The driving member or members may comprise a constant speed lineshaft, internal combustion engine, or, as shown, electric motor 1. In multiple drives, a common drive line-shaft may be used. In Fig. 1, wherein the torque requirement of a load 60, which may be an agitator, is dependent upon the load speed, a substantially constant driving torque at the load is obtained by arranging the torque-measuring device 20 between the gear 10 and the load 60, the speed at the load being adjusted by the automatic actuation of the gear control motor 16 until the loadtorque-value voltage at the potentiometer 40 equals the voltage at the manually pre-set demand control potentiometer 50 which may be calibrated in load driving torque units. In Fig. 2 (not shown), wherein the load torque requirement varies inversely with the load speed, a substantially constant loaddriving power is obtained by maintaining constant torque at constant speed (i.e. constant power) at the input to the gear 10 by arranging the torque-measuring device 20 between the motor 1 and the gear 10. In this arrangement the demand control potentiometer 50 may be calibrated in load driving power units. For balanced torque distribution in multiple drives arranged in series for conveyer belt drives or web or strip-processing drives, or in parallel as in Fig. 3 (not shown), one master drive and one or more follower drives have each the torque measuring device 20 arranged between the gear 10 and the load as in Fig. 1. The gear control motor of the master drive is regulated manually for speed selection and the potentiometer controlled by its torque-measuring device is the torque demand control common for all the follower drives which each have gear control motors regulated by voltage difference as in Fig. 1. By suitably arranging the potentiometer resistor dimensions and the torque-measuring device spring tensions of the master and follower drives the total load driving torque may be divided in any desired proportion, each of the follower drives being regulated to a speed at which the load driving torque required of it occurs. In the winding device of Fig. 4 (not shown), wherein the arrangement is similar to that of Fig. 2 (not shown), above, the manually pre-set demand control potentiometer 50 is itself controlled via its supply lines, by a further potentiometer the tapping of which is moved with rotation of the gear-control motor 16, thus varying the tension of the wound material by varying the input torque to the gear 10 in accordance with the gear ratio which is automatically adapted to the changing diameter of the wound material. For restoration of an original maximum speed on recommencement of the winding operation with an empty drum, actuation of a multiple switch disconnects the potentiometers 40, 50, and connects the gearcontrol motor adjusted potentiometer and an opposing speed demand control potentiometer to the relay R to vary the gear ratio in a sense to annul the voltage difference existing between the connected opposing potentiometers. The Fig. 4 (not shown), arrangement may be used for unwinding material from a wound drum, the motor 1 becoming a brake generator. To prevent undesirable load-speed increase in the event of tearing of material in a series multiple drive or in the winding device of Fig. 4 (not shown), disconnectable trailing switch means cuts out the gear control motor 16 on, or after a predetermined number of control motor revolutions following control deviation.